Rails on portal crane cross beams tend to wear and get rough after years of heavy loads being run on them. This causes vibration, which accelerates metal fatigue. It also creates an increasingly rough ride for an operator positioned in an operators cab of the portal crane. These rails can be 300 feet long and are very expensive to replace, so a method of servicing them in place is required.
Similar problems relating to servicing rails have been encountered in other industries. Examples of solutions proposed in the prior art include: U.S. Pat. No. 4,135,332 (Theurer 1979) entitled “Rail Grinding Machine”; U.S. Pat. No. 5,575,709 (Hertelendi et al 1996) entitled “Rail Grinding Machine For Grinding Rails Of A Track”; U.S. Pat. No. 5,735,734 (Hertelendi 1998) entitled “Apparatus for Grinding Rails”; U.S. Pat. No. 6,358,149 (Hempel 2002) entitled “Railroad Rail Support For A Grinder”; and U.S. Pat. No. 6,669,533 (Huboud-Peron 2003) entitled “Rail Profile Grinding Machine”.